When God seeks out the rebellious son who flees far from his sight, he does so with particular insistence and love. God traveled the tortuous roads of sinners through his Son, Jesus Christ, who, bursting onto history's stage, is presented as "the Lamb of God, who takes away the sins of the world" (Jn 1: 29). Here are the first words he says in public: "Repent, for the kingdom of heaven is at hand!" (Mt 4: 17). An important term appears which Jesus will repeatedly explain in words and deeds: "Repent", in Greek metanoeite, that is, make a metanoia, a radical change of mind and heart. It is necessary to turn away from evil and to enter the kingdom of justice, love and truth which is being established.
The trilogy of parables on divine mercy collected by Luke in chapter 15 of his Gospel is the most striking depiction of how God actively seeks out and lovingly awaits his sinful creature. Through his metanoia or conversion man returns, like the prodigal son, to embrace the Father who has never forgotten or abandoned him.
In commenting on this parable of the father who is prodigal with his love towards the son who was prodigal with his sin, St Ambrose introduces the presence of the Trinity: "Rise, run to the Church: here is the Father, here is the Son, here is the Holy Spirit. He runs out to meet you, for he hears you as you reflect within the secrecy of your heart. And while you are still at a distance, he catches sight of you and starts to run. He sees into your heart, he runs out so that no one will detain you, and futhermore he embraces you.... He throws his arms around your neck, to lift up what had been lying on the ground and to enable someone oppressed by the burden of sin and looking down at earthly things to turn his gaze again to heaven, where he should have been seeking his Creator. Christ throws his arms around your neck because he wants to remove the yoke of slavery and put a gentle yoke upon it" (In Lucam VII, 229-230).
A person's encounter with Christ changes his life... On the Cross there is an extreme act of forgiveness and hope given to the evil-doer, who makes his metanoia when he arrives at the final frontier between life and death, and says to his companion: "we are receiving the due reward for our deeds" (Lk 23: 41). To the one who implores him: "Remember me when you come in your kingly power", Jesus replies: "Truly, I say to you, today you will be with me in paradise" (cf. Lk 23: 42-43). Thus Christ's earthly mission, which began with the invitation to repent in order to enter the kingdom of God, ends with a conversion and an entry into his kingdom.
The Apostles' mission also began with a pressing invitation to conversion. Those who heard Peter's first address felt cut to the heart and anxiously asked "What should we do?". He said in reply: "Repent (metanoesate) and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit" (Acts 2: 37-38). Peter's answer was promptly accepted: "about three thousand souls" were converted that day (cf. Acts 2: 41). After the miraculous healing of a crippled man, Peter exhorted them again. He reminded the residents of Jerusalem of their horrible sin: "You denied the Holy and Righteous One, ... and killed the Author of life" (Acts 3: 14-15), but he mitigated their guilt, saying: "Now, brethren, I know that you acted in ignorance" (Acts 3: 17); he then called them to conversion (cf. 3: 19) and gave them immense hope: "God sent him to you first, to bless you in turning every one of you from your wickedness" (3: 26).
In a similar way, the Apostle Paul preached repentance. He says so in his address to King Agrippa, describing his apostolate as follows: "I declared" to everyone, "also to the Gentiles, that they should repent and turn to God and perform deeds worthy of their repentance" (Acts 26: 20; cf. 1 Thes 1: 9-10)". Paul taught that "God's kindness is meant to lead [us] to repentance" (Rom 2: 4). In the book of Revelation it is Christ himself who repeatedly urges repentance. Inspired by love (cf. Rv 3: 19), the exhortation is vigorous and expresses all the urgency of repentance (cf. Rv 2: 5, 16, 21-22; 3: 3, 19), but is accompanied by wondrous promises of intimacy with the Saviour (cf. 3: 20-21).
The door of hope is therefore always open to every sinner. "Man is not left alone to attempt, in a thousand often frustrated ways, an impossible ascent to heaven. There is a tabernacle of glory, which is the most holy person of Jesus the Lord, where the divine and the human meet in an embrace that can never be separated. The Word became flesh, like us in everything except sin. He pours divinity into the sick heart of humanity, and imbuing it with the Father's Spirit enables it to become God through grace" (Orientale lumen, n. 15).